Watch him play. He has a unique set of tools and mindset on the court.
Defensive playmaking is defense. It’s the thing that translates. Was Draymond Green a great defender as an underclassment? Not really. Did he display an incredible knack for making plays? Yes. He was a specialist and blocking jump shots, stripping and getting deflections. Josh Jackson’s D translates very well.
You can’t let a measurement matter when the player clearly defies the measurements on the court. There are so many cases where Jackson displays great length, I don’t have to go in to it. He plays big. I’d argue bigger than Iguodala did at the same age.
Which brings me to athleticism. JJ is on par with AI. If he can’t jump as high, he’s faster. If he’s not as strong, he’s quicker and more agile. I just don’t see the gap you speak of. JJ is an elite athlete with a better J and nicer looking release. He does need to get his set up mechanics cleaned up as he flings the ball back at different distances, but everything else looks better than AI.